Hair Cutter with Improved Energy Storage

Abstract

A hair cutter with an energy storage device is provided. The energy storage device is connected to the motor through a circuit that powers the motor to oscillate a translating blade over a stationary blade. When the hair cutter is operating the energy storage device is discharged. When the energy storage device is completely discharged, the hair cutter is recharged, for example, by connecting the hair cutter to a power outlet. The electrical circuit connects the energy storage device to a voltage and/or current input to charge the energy storage device. In various specific embodiments, the energy storage device is a hybrid capacitor that includes characteristics of a supercapacitor and a lithium-ion battery.

What is claimed is: 
     
         1 . A hair cutter comprising:
 a handle having an enclosure defining an interior;   a stationary blade fixed to the enclosure, the stationary blade including a first set of cutting teeth;   a translating blade including a second set of cutting teeth and slidably supported relative to the stationary blade such that the first set of cutting teeth and the second set of cutting teeth cooperate to cut hair when the translating blade is slid relative to the stationary blade;   an electric motor supported within the interior of the handle and having first and second contacts, the electric motor being fixed to the enclosure and coupled to the translating blade to slide the translating blade relative to the stationary blade when electrical energy is applied to the electric motor;   a capacitor having a capacitance of at least 150 Farads and a volume less than 1 cubic inch, the capacitor comprising:
 a first electrode; 
 a second electrode, the first and second electrodes separated by an ion-permeable membrane; and 
 an electrolyte, the electrolyte connecting the first and second electrode; and 
   a circuit for connecting the first and second contacts of the electric motor to the first and second electrodes of the capacitor to selectively apply electrical energy from the capacitor to the electric motor;   wherein an energy storage capacity of the capacitor is less than 0.3 watt hours.   
     
     
         2 . The hair cutter of  claim 1 , further comprising a second capacitor connected to the capacitor in parallel. 
     
     
         3 . The hair cutter of  claim 1 , wherein the capacitor is a hybrid capacitor supported within the interior. 
     
     
         4 . The hair cutter of  claim 3 , wherein the hybrid capacitor has a capacitance of at least 200 Farads and a volume less than 0.5 cubic inches. 
     
     
         5 . The hair cutter of  claim 1 , wherein the electric motor is a direct current electric motor. 
     
     
         6 . The hair cutter of  claim 5 , wherein the electric motor is a brushless direct current motor. 
     
     
         7 . The hair cutter of  claim 1 , further comprising a yoke attached to the translating blade and the electric motor includes a rotatable shaft having an offset which couples the electric motor to the translating blade via its interaction with the yoke. 
     
     
         8 . The hair cutter of  claim 1 , the circuit further comprising a regulator between the capacitor and the electric motor, wherein the regulator is at least one of a buck converter, a boost converter, a buck-boost converter, and a pulse-width modulator. 
     
     
         9 . The hair cutter of  claim 1 , wherein the hair cutter has a run time of at least 5 minutes. 
     
     
         10 . A hair cutter comprising:
 a handle having an enclosure defining an interior;   a stationary blade fixed to the enclosure, the stationary blade including a first set of cutting teeth;   a translating blade including a second set of cutting teeth and slidably supported relative to the stationary blade such that the first set of cutting teeth and the second set of cutting teeth cooperate to cut hair when the translating blade slides relative to the stationary blade;   an electric motor supported within the interior of the handle and having first and second contacts, the electric motor being fixed to the enclosure and coupled to the translating blade to slide the translating blade relative to the stationary blade when electrical energy is applied to the electric motor;   an energy storage device supported within the interior of the handle, the energy storage device comprising:
 a first capacitor comprising:
 a first electrode; 
 a second electrode, the first and second electrodes separated by an ion-permeable membrane; and 
 an electrolyte, the electrolyte connecting the first and second electrodes; and 
 
 a second capacitor connected to the first capacitor in parallel, the second capacitor comprising:
 a third electrode; 
 a fourth electrode, the third and fourth electrodes separated by an ion-permeable membrane; and 
 an electrolyte, the electrolyte connecting the third and fourth electrodes; and 
 
   a circuit for connecting the first and second contacts to the energy storage device to selectively apply electrical energy from the energy storage device to the electric motor.   
     
     
         11 . The hair cutter of  claim 10 , wherein the energy storage device has a capacitance greater than 200 Farads and a volume less than 1 cubic inch. 
     
     
         12 . The hair cutter of  claim 10 , wherein the energy storage device has a capacitance greater than 400 Farads and a volume less than 1 cubic inch. 
     
     
         13 . The hair cutter of  claim 10 , wherein the first capacitor and second capacitor are hybrid capacitors. 
     
     
         14 . The hair cutter of  claim 10 , wherein the electric motor is a brushed direct current motor. 
     
     
         15 . The hair cutter of  claim 10 , wherein, when the energy storage device is charged for 3 minutes, the hair cutter has a run time of at least 10 minutes. 
     
     
         16 . A cordless hair cutter powered by rechargeable electrical energy storage device, the cordless hair cutter comprising:
 a handle having an enclosure defining an interior;   a stationary blade fixed to the enclosure, the stationary blade including a first set of cutting teeth;   a translating blade including a second set of cutting teeth and slidably supported relative to the stationary blade such that the first set of cutting teeth and the second set of cutting teeth cooperate to cut hair when the translating blade slides relative to the stationary blade;   an electric motor having first and second contacts, the electric motor being fixed to the enclosure and coupled to the translating blade to slide the translating blade relative to the stationary blade when electrical energy is applied to the electric motor;   an energy storage device supported within the interior; and   a circuit for connecting the first and second contacts to the energy storage device to selectively apply electrical energy from the energy storage device to the electric motor;   wherein the energy storage device has a ratio of charge time to run time of about 1 to 5.   
     
     
         17 . The cordless hair cutter of  claim 16 , the energy storage device further comprising:
 a first hybrid capacitor comprising:
 a first electrode; 
 a second electrode, the first and second electrodes separated by an ion-permeable membrane; and 
 an electrolyte, the electrolyte connecting the first and second electrodes; and 
   a second hybrid capacitor connected to the first hybrid capacitor in parallel, the second hybrid capacitor comprising:
 a third electrode; 
 a fourth electrode, the third and fourth electrodes separated by an ion-permeable membrane; and 
 an electrolyte, the electrolyte connecting the third and fourth electrodes. 
   
     
     
         18 . The cordless hair cutter of  claim 17 , wherein a total energy storage capacity of the energy storage device is less than 0.5 watt hours. 
     
     
         19 . The cordless hair cutter of  claim 16 , the circuit further comprising a regulator between the energy storage device and the electric motor, wherein the regulator is at least one of a buck converter, a boost converter, a buck-boost converter, and a pulse-width modulator. 
     
     
         20 . The cordless hair cutter of  claim 16 , wherein the energy storage device has a capacitance greater than 400 Farads and a volume less than 1 cubic inch.